Improvement in bridge-coluivins



J. ZELLW EG ER.

Bridge-Columns.

Patented Dec. 16,1873.,

JOHN znLLwnenn, or LOUISVILLE, KENTUCKY.

IMPROVEMENT IN BRIDGE-COLUMNS.

Specification forming part ofLetters Patent No. 145,545, dated December 16, 1873; application filed October 20, 1873.

To all whom it may' concern.

Beit known that I, JOHN ZnLLwEGnn, of

' Louisville, in the county of Jefferson and State y rig-'idly the several members or main bars for a post or brace by means of one or more bars ofmetal,called truss-bars, bent in such a m anner around al central axis as to form either curved, screw-shaped, or winding lines,si1ni lar to the windings of the threads of a screw, or so as to form angular winding lines, either with equal or unequal straight parts, similar to winding stairs built of straight sections.

In trussed braces or posts as hitherto designed or built, the main bars are either connected by zigzag-shaped truss-bars, or by a number of short straight bars, arranged in oblique positions between the main bars, with which they form a series of triangles. The zigzag-shaped truss-bar is made by bending a suitable bar, at nearly equidistant points, forward and backward alternately, which bending is donein one and the same plane, but in two different directions.

Trussed braces or posts with the new or winding truss-bars as connecting parts differ essentially from either of the two kinds of braces or posts just mentioned in the shape of the truss-bars, as said winding truss-bars are never straight for their entire length, but are bent, in one and the same direction, around a central axis, so as to form a kind of spiral line, which cannot be in one and the same plane.

The objects of the invention are, iirst, to al low of the construction of open posts or columns; second, to lessen the cost of manufac ture of such posts; third, to make the trussed e posts or braces more convenient for pin-connections.

Figurelis an elevation of an open post made out of four T-beams as main bars, riveted to a uniformly screw-shaped winding truss-bar, or spiral trussbar. Fig. 2 is a top view of the same. Fig. 3 is an elevation of an open post made out of four angle-irons as main bars, riveted to an angular winding truss-bar. Fig. 4 is a top view of the same. Fig. 5 is a front elevation of a trussed brace with only two flat bars as main bars, riveted to the short sides of an angular winding truss-bar. The truss bar, in this elevation, shows similar to an ordinary zigzag bar, although it is an angularwinding trussbar. The trusscd brace shown in this figure is tapering toward one end. Fig. 6 is a side elevation of the same with one main bar taken ott. This elevation shows more plainly the manner in which the truss-bar is bent. Fi 7 i's a bottom view of the same.

Similar letters of reference indicate corresponding parts.

A, main bars; B, truss-bars; G, end rings; D, pin.

The main bars or members of a built post or brace may be held together by one or more winding truss-bars. It' there is more than one, they can be wound inthe same or in different directions. In the latter case it would bc of advantageto rivetthe truss-bars together at their intersections. The main bars maybe secured to the truss-bars by one or more rivets or bolts at each intersection. The several windings of the truss-bars may be equal in size from end to end of the post or brace; or they may become smaller or larger, either from one end toward the other end, or from the center toward the ends.

Since the winding truss-bar of a brace or post is, in all its points, some distance away from its axis, it is practicable to run a pin centrally through the main bars without interfering with the truss-bar-a feat-ure very desirable in in an y cases.

By the use of a winding truss-bar as a connecting part between the main bars of a built post or brace, it is possible to construct an. open post 7 or open brace77 the interior of which can be conveniently inspected and painted.

In some cases the truss-bars may be outside of the main bars. The windings of a truss-bar may be terminated by bending it atV right angles to the central axis of the post or brace.

In some cases a ring or an angular band would do good service to keep the ends of the main bars in their relative positions. Flat plates or rings or angular bands of suflicient width may be secured to the main bars to facilitate piineoiiiieeticiis.

2 1&5545

The winding truss-bars can conveniently be made by winding suitable bars around properly-shaped pattern-beams. The metal strap for the truss-bar maybe heated in a furnace Ot' suitable length, and then pulled out by winding it over the pattern-beams, which would have to revolve around their longitudinal axis, and, at the same time, be in motion along said axis.

It would be advantageous to take the bars directly from the rolls between which they were made, and bend them over the pattern-beams without reheatinn.

In connection with the windin g up of the trussbars they will have to be hammered or pressed to a close fit around the pattern-beains, in which operation the contraction of the bars while cooling off can be successfully made use ot'.

The pattern around which the truss-bars have to be wound may consist either of one suitably-shaped beam,called a pattern-beam,77 or of two or more such beams. In the latter ease the pattern-beams have to be set at any desired distance apart, land at any divergence or inclination toward cach other by means of struts, stay-bolts, or wedges. On the outside of the pattern-beams suitable keys or saddles may be mounted, over which to wind the trussbars. By this arrangement the finished trussbars couldbereadily removedfrom the patterns.

If the pattern has only one beam, the use of saddles would be of special advantage, as it would only be necessary to employ saddles or keys of various sizes and shapes to make the windings of the truss-bars Yof any desired size and shape. A pattern with one single beam, upon which various saddles or keys can be mounted and secured, has the great advantage of being simpler and less liable to get out of order than one with two or more pattern-beams. Said keys or saddles could be made to answer as punch-blocks, on which to punch the necessaryholes in the truss-bars. After the punching of these holes the main bars might be secured in their proper places before removing the truss-bars from the pattern-beams. The truss-bar, when being wound up, may have to `go through between two rollers for the purpose of being stretched.

rlhe pattern-beams may be mounted on tables or iframes, which would have to run longitudinally on slides, rollers, or small wheels, similar to the carriages in saw-mills.

The rotary motion of the pattern-beams may be obtained, through suit-able gearings, from the longitudinal motion of the carriages.

I claim as my invent-ion- The rigid connection of the main bars A of a built post, brace, or column by means of curved or angular winding truss-bars B, substantially as described.

J OHN ZELLVVEGER.

Vitnesses ALBERT JANEGK., ADOLF SOHNYDER. 

